package com.atguigu.apitest.transform;

import com.atguigu.apitest.beans.SensorReading;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;

/**
 * @author Administrator
 */
public class TranformTest2_RollingAggregation {
    public static void main(String[] args) throws  Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);
        //从文件读取数据
        DataStream<String> inputStream = env.readTextFile("data/flink/sensor.txt");
        //转换成sensorReading类型
        DataStream<SensorReading> dataStream = inputStream.map(new MapFunction<String, SensorReading>() {
            @Override
            public SensorReading map(String value) throws Exception {
                String[] fields = value.split(",");
                return new SensorReading(fields[0], new Long(fields[1]), new Double(fields[2]));
            }
        });
        //分组
        KeyedStream<SensorReading, String> keyedStream = dataStream.keyBy(value -> value.getSensorId());
        //方法引用
        //KeyedStream<SensorReading, String> keyedStream1 = dataStream.keyBy(SensorReading::getId);
        //滚动聚合，取当前最大的温度值
        SingleOutputStreamOperator<SensorReading> resultStream = keyedStream.maxBy("temperature");
        resultStream.print();
        env.execute();

    }

}
